The program described in this proposal is designed to develop a Digestive Disease Core Center for the Study of Diarrhea and Secretory Processes at the New England Medical Center in association with the Tufts University School of Medicine. The Center will serve as a focus for research on diarrheal disease. Many basic scientists and clinical investigators in the Medical School complex are at a stage in their work where a Core Center is now essential to the research effort. The Center will provide important opportunities to expand research possibilities in digestive disease. The laboratory of the Core Center will be (A) a central cell culture facility for the study of epithelial cells in culture to allow evaluation of their function and interaction with pathogenic organisms, and for large scale culture of Giardia lamblia and Entamoeba histolytica, and (B) a fluorescent microscope unit with image intensification capabilities allowing for study of intracellular pH and Ca++ at the organelle level. The collaborating scientists in the Core Center will be 21 investigators with independent projects, but with research interests which overlap in a fashion which will benefit from the interrelationships made possible by the Center. During the first 12 months, the planning group will be preparing the final Core Center proposal. A planning coordinator will be hired to assist the Program Director in organizing the proposal, meeting with the Scientific Advisory Board, carrying out administrative arrangements, and interacting with the design and layout personnel. During the developmental phases of the grant preparation, interactions with the cooperating investigative units will be established, including departments of basic science, clinical departments, the USDA Human Nutrition Center on Aging, the Tufts Veterinary School, the Sackler School of Biomedical Sciences and the Tufts University School of Medicine.